RT Journal Article SR Electronic(1) A1 Kuri, Thomas A1 Zhang, Xiaonan A1 Habjan, Matthias A1 Martínez-Sobrido, Luis A1 García-Sastre, Adolfo A1 Yuan, Zhenghong A1 Weber, FriedemannYR 2009 T1 Interferon priming enables cells to partially overturn the SARS coronavirus-induced block in innate immune activation JF Journal of General Virology, VO 90 IS 11 SP 2686 OP 2694 DO https://doi.org/10.1099/vir.0.013599-0 PB Microbiology Society, SN 1465-2099, AB SARS coronavirus (SARS-CoV) is known to efficiently suppress the induction of antiviral type I interferons (IFN-α/β) in non-lymphatic cells through inhibition of the transcription factor IRF-3. Plasmacytoid dendritic cells, in contrast, respond to infection with production of high levels of IFNs. Here, we show that pretreatment of non-lymphatic cells with small amounts of IFN-α (IFN priming) partially overturns the block in IFN induction imposed by SARS-CoV. IFN priming combined with SARS-CoV infection substantially induced genes for IFN induction, IFN signalling, antiviral effector proteins, ubiquitination and ISGylation, antigen presentation and other cytokines and chemokines, whereas each individual treatment had no major effect. Curiously, however, despite this typical IFN response, neither IRF-3 nor IRF-7 was transported to the nucleus as a sign of activation. Taken together, our results suggest that (i) IFN, as it is produced by plasmacytoid dendritic cells, could enable tissue cells to launch a host response to SARS-CoV, (ii) IRF-3 and IRF-7 may be active at subdetectable levels, and (iii) SARS-CoV does not activate IRF-7., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.013599-0